A Gigabit capability Passive Optical Network (GPON) system generally includes an Optical Line Terminal (OLT) on a network side and an Optical Network Unit (ONU) on a user side. One OLT may be connected to multiple ONUs, and signals are distributed to multiple ONUs using a splitter on the user side.
In the GPON system, a packet sent by the OLT to each ONU is sent using a broadcast multicast packet manner. That is, each packet can be received by each ONU, the ONU determines whether the packet is sent to the ONU, and then discards a packet that is not sent to the ONU.
In the prior art, a multicast packet sent by an OLT to multiple ONUs only needs to be sent once using a broadcasting manner, and each ONU can receive a packet that is considered to be sent to the ONU. In this case, network bandwidth may be saved. However, only some ONUs need the multicast packet, which, however, is not needed by each ONU. As a result, the OLT cannot control traffic of the multicast packet, where the traffic is network transmission bandwidth, and some ONUs receive the packet that they do not need, thereby wasting traffic. If the OLT does not collect statistics on the traffic of the multicast packet, traffic statistics on ONUs that need the multicast packet are inaccurate.